Heretofore it was known to blend petrolatums and petroleum waxes with various materials to impart a carboxylic character to the petrolatums and waxes. In Hutchinson, U.S. Pat. No. 3,914,131 granted Oct. 21, 1975, there is disclosed blending high molecular weight branched monocarboxylic acids with microcrystalline petroleum wax and mixed glycerols of saturated mono- and dicarboxylic acids. The resultant blended wax was said to be useful in cosmetic formulations. Davis, U.S. Pat. No. 4,035,514 granted July 12, 1977, discloses blends of petrolatum with cetyl alcohol, lanolin alcohols, and alkoxylated fatty acid esters of sorbitol for water dispersion cream uses. Seigel, U.S. Pat. No. 3,919,430 granted Nov. 11, 1974, also discloses blending petrolatums with alcohols and esters for water-in-oil emulsions.
While in the prior art the use of petrolatum and microcrystalline wax is abundantly disclosed and in U.S. Pat. No. 3,914,131, cited above, the use of oxidized microcrystalline waxes is suggested, there is no indication that oxidized petrolatum, as hereinafter disclosed, is usable to form stable water-in-oil emulsions for personal care preparations.
Oxidation of petrolatum to provide, in situ, a degree of carboxylic functionality was generally limited to modest levels of oxidation. More specifically, oxidized petrolatums with relatively low acid numbers of up to about 50 were regarded as useful in rust prevention formulations, but were not considered for personal care preparations. In the first place, their acid numbers were low and they exhibited undesirable aesthetic characteristics, particularly as to color (dark) and odor. Upon increasing the acid number by oxidation, the petrolatums would rapidly take on characteristics which rendered them unsuitable for use in personal care preparations.
In parent U.S. application Ser. No. 074,023, filed 10 Sept. 1979, the following patents were recorded during prosecution:
______________________________________ No. Patent No. Date Patentee or Agent Country ______________________________________ (1) 12,348 6/1900 Boleg Great Britain (2) 429,185 5/1935 Lean " (3) 1,004,174 9/1965 Shiseido " (4) 1,553,145 12/1968 L'Oreal France ______________________________________
Reference (1), supra, teaches, simply, oxidation of mineral oils in the presence of caustic soda lye to make them water-soluble and useful in medicaments. Reference (2) prepares pesticides by oxidizing waxes or liquid petroleum distillates at elevated temperatures and pressures in the presence of a "known oxidation catalyst", and by subsequently saponifying saponifiables in the resultant reaction mixture. References (3) and (4) are not concerned with oxidized petrolatum, let alone the emulsifiable compositions and stable emulsified W/O personal care preparations herein described.
As will be seen hereinafter, the present invention provides an emulsifiable personal care preparation wherein the petrolatum is readily emulsifiable and provides a stable emulsion which is aesthetically acceptable in odor and color.